[downwithbgp]

dn42 [0] also has, effectively, a playground for BGP. While I don't have experience with it personally, it seems to be just a VPN network with private addressing where you can find other folks to form neighbors with.

That being said, you don't need to be online to play with routing protocols. A couple VMs with your favourite flavour of Cisco/Juniper virtualised switches do just as well. Some of the most popular projects to simplify VM spin-up and interconnections are GNS3 [1] and EVE-NG [2].

[0] https://dn42.eu

[1] https://gns3.com

[2] https://eve-ng.net

edit: link formatting

[rrmm]

I'm surprised large users don't have a simulate-before-issuing BGP-changes policy given the number of times BGP has bitten people. I imagine the devil would be in the differences between your sim and actual behavior, but it might save a few people a lot of pain.